1. Field of the Invention
The present invention relates to an image transmission device and an image transmission system. More particularly, the present invention relates to an image transmission device and a system utilizing the image transmission device to transmit images photographed by a television camera, such as a CCD camera, to remote locations, and to observe the same image at multiple separate locations.
2. Description of the Related Art
Devices are known which allow a person at a remote location to observe an image of a subject transmitted from another location. For example, devices are known which allow specialists at remote locations to observe a pathological examination by transmitting a subject image to the remote locations. The subject image is displayed on a television monitor at the location from which the subject image is transmitted (transmission location) and the subject image is also displayed at the remote location (reception location). The image displayed on the respective television monitors can then be discussed via telephone.
The above-described type of image transmission device is disclosed, for example, in Japanese Laid-Open Utility Model Hei 4-11960, Japanese Laid-Open Utility Model Hei 4-119184, and Japanese Laid-Open Patent Publication Number Hei 5-176226. However, it is difficult to accurately refer to particular parts of a displayed subject image with the known types of image transmission devices. Specifically, when discussing a part of the image displayed at one location, e.g., the transmission location, it may be difficult to accurately ascertain, at the reception location, the part of the subject image being discussed.
Therefore, to refer to particular parts of a displayed image, an arrow-like indicator which is manipulated using a mouse is synthesized on the image of the subject in the television monitor. By projecting the arrow-like indicator on the same part of the subject image at both the transmission location and the reception location, it becomes possible to accurately refer to a particular part of the subject image being discussed. Moreover, by displaying the tracks of the arrow-like indicator, it becomes possible to indicate a part of a subject which should be cut, or to clearly designate a necessary range while discussing a subject.
It is comparatively convenient to indicate specific locations on the subject with the arrow-like indicator projected on the image transmission device and which moves freely on the screen of the television monitor. However, during a pathological examination, for example, when giving directions from a remote location regarding preparing a specimen from an organ at a transmission location, it is sometimes difficult to indicate the exact location and direction of a cut. Therefore, a system is needed for conveniently and accurately referring to locations on a subject image which is transmitted to a remote location for observation.